Millwork sanding sponge

ABSTRACT

The present invention relates to a hand-held abrasive article. In one embodiment, the hand-held abrasive article includes an elongated resilient body having a perpendicular cross-sectional surface. The cross-sectional surface of the resilient body includes at least one internal right angle, at least one internal acute angle, at least one internal obtuse angle, and at least one curved portion. At least a portion of the resilient body is coated with abrasive.

BACKGROUND

The present invention relates to resilient flexible abrasive devicestypically referred to as sanding sponges, and more particularly, to ahand-held, disposable abrasive article for sanding a variety of surfaceshapes and configurations.

Common sanding tasks calling for considerable detail work or access tosmall confined areas, or for sanding contoured surfaces, often requirethat the surfaces be hand sanded. Hand-held sanding devices for thispurpose have essentially consisted of a sanding block for holdingconventional sandpaper wrapped over the block. By using a sanding blockas a sandpaper holder, hand-applied sanding forces on the sandpaper canbe increased and more evenly distributed.

The difficulty with the above-mentioned prior sanding devices is thenecessity of installing or wrapping a separate piece of sandpaper aroundthe device. This installation or wrapping process presents someinconvenience to the user. For example, if the paper is improperlyinstalled, it is susceptible to falling off. Also, the device requiresthe purchase of separate sheets of sandpaper that is a furtherinconvenience in terms of the amount of supplies needed.

U.S. Pat. No. 4,887,396 (Lukianoff) discloses a hand-sized sandingdevice that eliminates the need for a separate sheet of sandpaper. Thesanding device is provided with its own integral abrasive surfaces thatcan be manufactured at a sufficiently low cost to be disposable. Thesanding device of Lukianoff can be conveniently used to hand sand avariety of standard, contoured, or shaped surfaces, such as trim ormolding surfaces, and for projecting into exactly defined areas.

Another type of sanding device is the resilient flexible sanding sponge.Sanding sponges generally include a layer of abrasive particles adheredto a foam body by a flexible adhesive. One such sanding sponge is the 3MSmall Area Sanding Sponge available from 3M, St. Paul, Minn. Typically,a user places the body against the palm of his or her hand and rubs theabrasive over a surface to be abraded. The flexible adhesive layer andthe foam body permit the layer of abrasive to conform to the surfacebeing abraded.

While such sanding sponges work well to abrade objects having flatsurfaces these sponges are not well suited to sand a variety ofcontoured surfaces because the foam body and/or the layer of flexibleadhesive is too stiff to conform to the contoured surface being abraded.A sanding sponge with high tear strength body layer is disclosed in U.S.Pat. No. 6,419,573 (Lise et al.).

Sanding sponges often only have a projecting right angle to sandperpendicular corners, and typically do not have a variety of projectingangles and curves. It may be necessary to sand surfaces that havecontours other than a perpendicular corner. Especially when sandingmillwork, it is often necessary to sand a variety of contoured surfaces.

SUMMARY

The present invention relates to a hand-held abrasive article. In oneembodiment, the hand-held abrasive article includes an elongatedresilient body having a perpendicular cross-sectional surface. Thecross-sectional surface of the resilient body includes at least oneinternal right angle, at least one internal acute angle, at least oneinternal obtuse angle, and at least one curved portion. At least aportion of the resilient body is coated with an abrasive.

In another embodiment, the hand-held abrasive article includes anelongated resilient body having a first end surface and a second endsurface. The hand-held abrasive article further includes a first planarmajor surface, a second planar major surface contiguous with the firstplanar major surface, a third planar major surface contiguous with thesecond planar major surface, a fourth planar major surface contiguouswith the third planar major surface, and a curved surface contiguouswith the fourth planar major surface and the first planar major surface.Each major surface and the curved surface extend between the first endsurface and second end surface. At least one of the first planar majorsurface, second planar major surface, third planar major surface, fourthplanar major surface, or curved surface is abrasive.

In another embodiment, the hand-held abrasive article includes aresilient body having a first end surface and a second end surface. Thehand-held abrasive article further includes a first planar majorsurface, a second planar major surface, a third planar major surface, afourth planar major surface, and a curved surface. Each major surfaceand the curved surface extend between the first end surface and secondend surface. The intersection of two of the planar major surfaces forman acute angle, the intersection of two of the planar major surfacesform an obtuse angle, and the intersection of two of the planar majorsurfaces form a right angle. At least one of the first planar majorsurface, second planar major surface, third planar major surface, fourthplanar major surface, or curved surface is covered with an abrasivematerial.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of an abrasivearticle according to the present invention.

FIG. 2 is a sectional view through line 2-2 of the abrasive article ofFIG. 1.

FIG. 3 is a sectional view of a second embodiment of an abrasive articleaccording to the present invention.

FIG. 4 is a sectional view of a third embodiment of an abrasive articleaccording to the present invention.

While the above-identified drawings and figures set forth one embodimentof the invention, other embodiments are also contemplated, as noted inthe discussion. In all cases, this disclosure presents the invention byway of representation and not limitation. It should be understood thatnumerous other modifications and embodiments can be devised by thoseskilled in the art, which fall within the scope and spirit of thisinvention. The figures may not be drawn to scale. Like referencenumbers, incremented by 100, have been used to denote like parts.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate the first embodiment of a resilient flexiblesanding sponge 20 according to the present invention. The sanding sponge20 includes a resilient body 22. The body 22 may be an open celled foammaterial.

The body 22 is generally elongated along a longitudinal axis with afirst end surface 28 and a second end surface 30. As shown in FIG. 1,the first and second end surfaces 28, 30 are generally planar andparallel to one another. However, the first and second end surface 28,30 may be non-planar and formed at any angle relative to the body 22.

The body 22 includes a first major surface 32, second major surface 34,third major surface 36, fourth major surface 38, and curved surface 40.As shown in FIG. 1, the first major surface 32, second major surface 34,third major surface 36, fourth major surface 38 are all generally planarand extend from the first end surface 28 to the second end surface 30.The first end surface 28 and second end surface 30 are generallyperpendicular to the major surfaces. The first major surface 32 iscontiguous with the second major surface 34. The second major surface 34is contiguous with the third major surface 36. The third major surface36 is contiguous with the fourth major surface 38.

The curved surface 40 is contiguous with both the fourth major surface38 and the first major surface 32. The curved surface 40 also extendsfrom the first end surface 28 to the second end surface 30.

FIG. 2 is a sectional view through line 2-2 of the sanding sponge 20 ofFIG. 1. At the cross-section of the body 22, the sanding sponge 20includes an obtuse angle 42, a right angle 44, an acute angle 46, and acurved portion 48. As shown in this embodiment, the sanding sponge 20includes only one, or a single obtuse angle 42, a single right angle 44,and a single acute angle 46. Each internal angle 42, 44, and 46 is ameasurement of the angle through the internal structure of the body 22,between the meeting of two generally planar major surfaces.

In the embodiment shown in FIGS. 1 and 2, the first major surface 32 andsecond major surface 34 meet to form the obtuse angle 42. The secondmajor surface 34 and third major surface 36 meet to form the right angle44. The third major surface 36 and fourth major surface 38 meet to formthe acute angle 46.

The curved portion 48 corresponds to the curved surface 40 and istherefore adjacent and continuous with the first major surface 32 andfourth major surface 38. The curved portion 48 includes a radius ofcurvature 50.

A flexible adhesive 24 is used to adhere a layer of abrasive particles26 to at least a portion of the body 22. The layer of abrasive particles26 is shown in FIG. 1 as being adhered to the first major surface 32,second major surface 34, third major surface 36, fourth major surface38, and curved surface 40. As shown in FIG. 1, the abrasive particles 26are not adhered to the first end surface 28 and second end surface 30.The abrasive particles 26 may be adhered to only a portion of the body22, or the abrasive particles 26 may be adhered to the entire body 22.

The flexible adhesive 24 bonds the layer of abrasive particles 26 to thebody 22 and adheres the abrasive particles 26 together while beingsufficiently flexible to conform with the body 22 to the contour of thesurface to be abraded by the sanding sponge 20. A flexible adhesiveformulation and method of applying it is described in U.S. Pat. No.6,059,850, herein incorporated by reference, which can be used to formthe layer of flexible adhesive 24.

A layer of hard anti-loading size coating can optionally extend over theflexible adhesive 24 and the abrasive particles 26 opposite the body 22.A hard anti-loading size coating formulated and applied using the methoddescribed in U.S. Pat. No. 6,059,850, herein incorporated by reference,is suitable for this purpose.

The body 22 may be constructed of open-cell polyurethane foam. Onesuitable open-cell polyurethane foam is 0H58K Foam available fromCarpenter Co. of Richmond, Va. In some embodiments, the body 22 may beconstructed from high tear strength felted urethane foam. Furtherdescription of suitable body materials can be found in U.S. Pat.Application Publication 20040038634, herein incorporated by reference.

The abrasive particles 26 may be any of the abrasive particles describedin U.S. Pat. No. 6,059,850, herein incorporated by reference,particularly including particles of aluminum oxide, ceramic, or siliconcarbide in the range of about 36 to 400 grit.

Sanding sponges are typically made by coating a liquid adhesive over oneor more surfaces of the body 22, depositing a layer of the abrasiveparticles 26 on the adhesive coated surface of the body 22, and thendrying the flexible adhesive 24. Further description of the flexibleadhesive and coating process is described in U.S. Patent Application20040038634, which is herein incorporated by reference.

The user can hold any portion of the sanding sponge 20 that allows forusing the necessary exterior projecting portion of the sanding sponge 20to contact the work surface. The body 22 preferably has a cross sectionof such a size that fits comfortably into the palm of a user's hand. Thecross sectional dimensions of the body 22 preferably are such that thefingers of the user's hand will not reach around or beyond the body 22and thereby greatly reduce the chances of the user experiencingdiscomfort in moving the sanding sponge 20 back and forth in use.

In one embodiment, at the cross-sectional dimension, the first majorsurface 32 has a length of approximately 2.0 to 2.5 inches, preferablyabout 2.2 inches, the second major surface 34 has a length ofapproximately 0.5 to 1.5 inches, preferably about 1.0 inches, the thirdmajor surface 36 has a length of approximately 3 to 4 inches, preferablyabout 3.5 inches, and the fourth major surface 38 has a length ofapproximately 2.0 to 2.5 inches, preferably about 2.2 inches.

In one embodiment, the obtuse angle is approximately 120 degrees, theacute angle is approximately 60 degrees, and the curved portion 48 has aradius of curvature of approximately 0.25 to 0.5 inches, preferably0.375 inches.

The body 22 is preferably resiliently deformable (i.e., indentable) whensqueezed by the thumb and fingers of the user's hand and thus is notlikely to slip from the hand even if the fingers are wet or greasy. Thebody 22 is somewhat resiliently axially compressible and acts as acushion between the user's hand and the work surface as the sandingsponge 20 is being pushed back and forth to perform the abradingfunction.

In one embodiment, at least one of the first major surface 32, secondmajor surface 34, third major surface 36, fourth major surface 38, andcurved surface 40 may be a structured surface. Structured surfaces aredisclosed and described in U.S. Pat. Application “Resilient StructuredSanding Article,” which is 3M file number 59662US002, filed on evendated, the disclosure of which is herein incorporated by reference.

FIG. 3 illustrates a cross sectional view of a second embodiment of aresilient flexible sanding sponge 120 according to the presentinvention. The sanding sponge 120 includes a body 122. The body 122 maybe an open-celled foam material.

The body 122 is generally an elongated along a longitudinal axis,similar to that shown in FIG. 1, with a first end surface and a secondend surface. The first and second end surfaces are generally planar andparallel to one another.

The body 122 includes a first major surface 132, second major surface134, third major surface 136, fourth major surface 138, and curvedsurface 140. The first major surface 132, second major surface 134,third major surface 136, fourth major surface 138 are all generallyplanar and extend from the first end surface to the second end surface.The first end surface and second end surface are generally perpendicularto the major surfaces. The first major surface 132 is contiguous withthe second major surface 134. The second major surface 134 is contiguouswith the third major surface 136. The third major surface 136 iscontiguous with the fourth major surface 138. The curved surface 140 iscontiguous with both the fourth major surface 138 and the first majorsurface 132.

At the cross-section of the body 122, the sanding sponge 120 includes anobtuse angle 142, a right angle 144, an acute angle 146, and a curvedportion 148. Each internal angle 142, 144, and 146 is a measurement ofthe angle through the internal structure of the body 122 between themeeting of two generally planar major surfaces.

In the embodiment shown in FIG. 3, the first major surface 132 andsecond major surface 134 meet to form the right angle 144. The secondmajor surface 134 and third major surface 136 meet to form the acuteangle 146. The third major surface 136 and fourth major surface 138 meetto form the obtuse angle 142. The curved portion 148 corresponds to thecurved surface 140 and is therefore adjacent and continuous with thefirst major surface 132 and fourth major surface 138. The curved portion148 includes a radius of curvature 150.

A flexible adhesive 124 is used to adhere a layer of abrasive particles126 to at least a portion of the body 122. The layer of abrasiveparticles 126 is shown in FIG. 3 as being adhered to the first majorsurface 132, second major surface 134, third major surface 136, fourthmajor surface 138, and curved surface 140. In one embodiment, at leastone of the first major surface 132, second major surface 134, thirdmajor surface 136, fourth major surface 138, and curved surface 140 maybe a structured surface.

FIG. 4 illustrates a cross sectional view of a third embodiment of aresilient flexible sanding sponge 220 according to the presentinvention. The sanding sponge 220 includes a body 222. The body 222 maybe an open-celled foam material.

The body 222 is generally an elongated along a longitudinal axis,similar to that shown in FIG. 1, with a first end surface and a secondend surface. The first and second end surfaces are generally planar andparallel to one another.

The body 222 includes a first major surface 232, second major surface234, third major surface 236, fourth major surface 238, and curvedsurface 240. The first major surface 232, second major surface 234,third major surface 236, fourth major surface 238 are all generallyplanar and extend from the first end surface to the second end surface.The first end surface and second end surface are generally perpendicularto the major surfaces. The first major surface 232 is contiguous withthe second major surface 234. The second major surface 234 is contiguouswith the third major surface 236. The third major surface 236 iscontiguous with the fourth major surface 238. The curved surface 240 iscontiguous with both the fourth major surface 238 and the first majorsurface 232.

At the cross-section of the body 222, the sanding sponge 220 includes anobtuse angle 242, a right angle 244, an acute angle 246, and a curvedportion 248. Each internal angle 242, 244, and 246 is a measurement ofthe angle through the internal structure of the body 222 and between themeeting of two generally planar major surface.

In the embodiment shown in FIG. 4, the first major surface 232 andsecond major surface 234 meet to form the right angle 244. The secondmajor surface 234 and third major surface 236 meet to form the obtuseangle 242. The third major surface 236 and fourth major surface 238 meetto form the acute angle 246.

The curved portion 248 corresponds to the curved surface 240 and istherefore adjacent and continuous with the first major surface 232 andfourth major surface 238. The curved portion 248 includes a radius ofcurvature 250.

A flexible adhesive 224 is used to adhere a layer of abrasive particles226 to at least a portion of the body 222. The layer of abrasiveparticles 226 is shown in FIG. 4 as being adhered the first majorsurface 232, second major surface 234, third major surface 236, fourthmajor surface 238, and curved surface 240. The abrasive particles 226are not adhered to the first end surface and second end surface.However, the abrasive particles may be adhered to the entire body 222 oronly a portion of the body 222. In one embodiment, at least one of thefirst major surface 232, second major surface 234, third major surface236, fourth major surface 238, and curved surface 240 may be astructured surface.

Although specific embodiments of this invention have been shown anddescribed herein, it is understood that these embodiments are merelyillustrative of the many possible specific arrangements that can bedevised in application of the principles of the invention. Numerous andvaried other arrangements can be devised in accordance with theseprinciples by those of ordinary skill in the art without departing fromthe spirit and scope of the invention. Thus, the scope of the presentinvention should not be limited to the structures described in thisapplication, but only by the structures described by the language of theclaims and the equivalents of those structures.

1. A hand-held abrasive article comprising: an elongated solid foamresilient body having a perpendicular cross-sectional surface; whereinthe cross-sectional surface of the resilient body comprises: at leastone internal right angle; at least one internal acute angle; and atleast one internal obtuse angle; and at least one curved portion;wherein at least a portion of the resilient body is coated withabrasive.
 2. The hand-held abrasive article of claim 1, wherein thecross sectional surface comprises: a single internal right angle.
 3. Thehand-held abrasive article of claim 1, wherein the cross sectionalsurface comprises: a single internal acute angle.
 4. The hand-heldabrasive article of claim 1, wherein the cross sectional surfacecomprises: a single internal obtuse angle.
 5. The hand-held abrasivearticle of claim 1, wherein the cross sectional surface comprises; asingle internal right angle; a single internal acute angle; and a singleinternal obtuse angle.
 6. The hand-held abrasive article of claim 5,wherein the single internal acute angle is approximately 60 degrees andthe single internal obtuse angle is approximately 120 degrees.
 7. Thehand-held abrasive article of claim 1, wherein the entire elongatedresilient body is coated with abrasive.
 8. The hand-held abrasivearticle of claim 1, wherein the elongated resilient body furthercomprises: a first end; and a second end, spaced from the first end;wherein the first end and second end are substantially planar andparallel to one another and perpendicular to the elongated resilientbody.
 9. The hand-held abrasive article of claim 1, wherein theelongated resilient body further comprises: a first planar majorsurface; a second planar major surface; a third planar major surface; afourth planar major surface; and a curved surface.
 10. The hand heldabrasive article of claim 9, wherein: the second planar major surface iscontiguous with the first planar major surface; the third planar majorsurface is contiguous with the second planar major surface; the fourthplanar major surface is contiguous with the third planar major surface;the curved surface is contiguous with the fourth planar major surfaceand the first planar major surface.
 11. The hand-held abrasive articleof claim 10, wherein: the intersection of the second planar majorsurface with the first planar major surface forms the obtuse angle; theintersection of the third planar major surface with the second planarmajor surface forms the right angle; and the intersection of the fourthplanar major surface with the third planar major surface forms the acuteangle.
 12. The hand-held abrasive article of claim 11, wherein: across-sectional length of the first planar major surface is at leastabout 2 inches; a cross-sectional length of the second planar majorsurface is at least about 0.5 inches; a cross-sectional length of thethird planar major surface is at least about 3 inches; a cross-sectionallength of the fourth planar major surface is at least about 2 inches;the curved portion has a radius of curvature of at least about 0.25inches; and the elongated resilient body comprises an overall lengthfrom about 2 inches to about 10 inches.
 13. The hand-held abrasivearticle of claim 1, wherein the resilient body comprises an open-celledfoam material.
 14. A hand-held abrasive article comprising: an elongatedsolid foam resilient body having a first end surface and a second endsurface: a first planar major surface extending between the first endsurface and second end surface; a second planar major surface extendingbetween the first end surface and second end surface and contiguous withthe first planar major surface; a third planar major surface extendingbetween the first end surface and second end surface and contiguous withthe second planar major surface; a fourth planar major surface extendingbetween the first end surface and second end surface and contiguous withthe third planar major surface; a curved surface extending between thefirst end surface and second end surface and contiguous with the fourthplanar major surface and the first planar major surface; wherein atleast one of the first planar major surface, second planar majorsurface, third planar major surface, fourth planar major surface, orcurved surface is abrasive.
 15. The hand-held abrasive article of claim14, wherein the elongated resilient body has a transverse cross-sectioncomprising: at least one internal right angle; at least one internalacute angle; and at least one internal obtuse angle.
 16. The hand-heldabrasive article of claim 15, wherein: the intersection of the firstplanar major surface and the second planar major surface forms theobtuse angle; the intersection of the second planar major surface andthe third planar major surface forms the right angle; the intersectionof the third major planar surface and the fourth planar major surfaceforms the acute angle.
 17. The hand-held abrasive article of claim 16,wherein: the acute angle is approximately 60 degrees; and the obtuseangle is approximately 120 degrees.
 18. The hand-held abrasive articleof claim 14, wherein the elongated resilient body comprises anopen-celled foam material.
 19. The hand-held abrasive article of claim14, wherein each of the first planar major surface, second planar majorsurface, third planar major surface, fourth planar major surface, andcurved surface is abrasive.
 20. A hand-held abrasive article comprising:a solid foam resilient body having a first end surface and a second endsurface; a first planar major surface extending between the first endsurface and second end surface; a second planar major surface extendingbetween the first end surface and second end surface; a third planarmajor surface extending between the first end surface and second endsurface; a fourth planar major surface extending between the first endsurface and second end surface; a curved surface extending between thefirst end surface and second end surface; wherein the intersection oftwo of the planar major surfaces form an acute angle, the intersectionof two of the planar major surfaces form an obtuse angle, and theintersection of two of the planar major surfaces form a right angle;wherein at least one of the first planar major surface, second planarmajor surface, third planar major surface, fourth planar major surface,and curved surface is covered with an abrasive material.
 21. Thehand-held abrasive article of claim 20, wherein: the second planar majorsurface is contiguous with the first planar major surface; the thirdplanar major surface is contiguous with the second planar major surface;the fourth planar major surface is contiguous with the third planarmajor surface; the curved surface is contiguous with the fourth planarmajor surface and the first planar major surface.
 22. The hand-heldabrasive article of claim 21, wherein: the intersection of the firstplanar major surface and the second planar major surface forms theobtuse angle; the intersection of the second planar major surface andthe third planar major surface forms the right angle; the intersectionof the third major planar surface and the fourth planar major surfaceforms the acute angle.
 23. The hand-held abrasive article of claim 22wherein: the acute angle is approximately 60 degrees. the obtuse angleis approximately 120 degrees.
 24. The hand-held abrasive article ofclaim 20, wherein the first planar major surface, second planar majorsurface, third planar major surface, fourth planar major surface, andcurved surface is abrasive.
 25. The hand-held abrasive article of claim20, wherein the resilient body comprises an open-celled foam material.